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United States Patent |
5,544,699
|
Robers
,   et al.
|
August 13, 1996
|
Oil cooler with a self-fastening, self-orienting pressure relief valve
Abstract
A simple, reliable bypass valve construction (50) is provided for use in
conjunction with a donut oil cooler (16) having an aluminum multi-piece
housing (28). The bypass valve construction (50) is easily accessible and
readily replaceable so as to lend itself to serviceability. The invention
is incorporated in an oil cooler (16) having a housing (28) with a coolant
inlet and outlet (42) and (44), and a surface (26) adapted to be sealed
against an oil filter (14). The oil cooler (16) includes a plurality of
interconnected heat exchange units (21) located inside the housing (28),
with an oil inlet to one of the units and an oil outlet from another of
the units. An oil bypass is provided through at least some of the
interconnected heat exchange units (21) and communicates with a bypass
outlet (62) in the housing surface (26). The bypass outlet (62) is
normally closed by a bypass valve (52) which includes a generally
C-shaped, sheet-like resilient flapper (54) with a valve element (56)
sized to close the bypass outlet (62) and located intermediate the ends of
the flapper (54). The ends of the flapper (54) have feet (64) and (66)
which are received in slots (68) and (70) in the housing surface (26) to
mount the flapper (54) on the surface (26) and to at least nominally
locate the valve element (56) with respect to the bypass outlet (62).
Inventors:
|
Robers; Kevin J. (Racine, WI);
Bretl; Richard A. (Union Grove, WI);
Gabbey; Lawrence W. (Racine, WI);
Kerkman; William J. (Racine, WI);
Kersher; Tod T. (Racine, WI)
|
Assignee:
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Modine Manufacturing Company (Racine, WI)
|
Appl. No.:
|
386418 |
Filed:
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February 10, 1995 |
Current U.S. Class: |
165/283; 165/103; 165/157 |
Intern'l Class: |
G05D 023/00 |
Field of Search: |
165/38,103,119,167,916,157
|
References Cited
U.S. Patent Documents
2360123 | Oct., 1944 | Gerstung et al.
| |
3743011 | Jul., 1973 | Frost | 165/38.
|
4360055 | Nov., 1982 | Frost | 165/38.
|
4561494 | Dec., 1985 | Frost.
| |
4580625 | Apr., 1986 | Yamanaka et al.
| |
4638856 | Jan., 1987 | Yamanaka et al. | 165/119.
|
4669532 | Jun., 1987 | Tejima et al. | 165/36.
|
4831980 | May., 1989 | Nasu et al.
| |
4967835 | Nov., 1990 | Lefeber.
| |
5236043 | Aug., 1993 | Armbruster et al.
| |
Primary Examiner: Flanigan; Allen J.
Attorney, Agent or Firm: Wood, Phillips, VanSanten, Clark & Mortimer
Claims
We claim:
1. In an oil cooler including a housing, a coolant inlet to the housing,
and coolant outlet from the housing, a housing surface adapted to be
sealed against an oil filter, a plurality of interconnected heat exchange
units within said housing, an oil inlet to one of said units, an oil
outlet from another of said units, an oil bypass through at least some of
said units, a bypass outlet in said housing surface and a bypass valve
normally closing said bypass outlet, the improvement wherein said bypass
valve comprises:
a generally C-shaped, sheet-like resilient flapper having ends;
a valve element carried by said flapper intermediate the ends of said
flapper and sized to close the bypass outlet;
feet on said ends; and
slots in said surface receiving said feet to mount said flapper on said
surface and to at least nominally locate said valve element with respect
to said bypass outlet.
2. The improvement of claim 1 wherein said feet on said ends are oppositely
directed.
3. The improvement of claim 1 wherein said feet on said ends are directed
radially outward.
4. The improvement of claim 1 wherein said valve element is sized to at
least partially enter said bypass outlet to close the same.
5. The improvement of claim 4 wherein at least one of said slots and said
feet are spatially arranged to preload said flapper and force said valve
element to at least partially enter said bypass outlet.
6. In an oil cooler including a housing, a coolant inlet to the housing,
and coolant outlet from the housing, a housing surface adapted to be
sealed against an oil filter, a plurality of interconnected heat exchange
units within said housing, an oil inlet to one of said units, an oil
outlet from another of said units, an oil bypass through at least some of
said units, a bypass outlet in said housing surface and a bypass valve
normally closing said bypass outlet, the improvement wherein said bypass
valve comprises:
a generally C-shaped, sheet-like resilient flapper having ends;
a valve element carried by said flapper intermediate the ends of said
flapper and sized to at least partially enter said bypass outlet to close
the same;
oppositely directed feet on said ends; and
slots in said surface receiving said feet to mount said flapper on said
surface and to at least nominally locate said valve element with respect
to said bypass outlet.
7. The improvement of claim 6 wherein said oppositely directed feet are
directed radially outward.
8. The improvement of claim 6 wherein at least one of said slots and feet
are spatially arranged to preload said flapper to force said valve element
to at least partially enter said bypass outlet.
9. In an oil cooler including a housing, a coolant inlet to the housing,
and coolant outlet from the housing, a housing surface adapted to be
sealed against an oil filter, a plurality of interconnected heat exchange
units within said housing, an oil inlet to one of said units, an oil
outlet from another of said units, an oil bypass through at least some of
said units, a bypass outlet in said housing surface and a bypass valve
normally closing said bypass outlet, the improvement wherein said bypass
valve comprises:
a generally C-shaped, sheet-like resilient flapper having ends;
a valve element intermediate the ends of said flapper and sized to close
the bypass outlet; and
cooperating means at or near said ends and on said surface for connection
together to mount said flapper on said surface and to at least nominally
locate said valve element with respect to said bypass outlet.
10. The improvement of claim 9 wherein:
said cooperating means is in the form of protrusions carried on said ends
and apertures in said surface receiving said protrusions to mount said
flapper on said surface and to at least nominally locate said valve
element with respect to said bypass outlet.
11. The improvement of claim 9 wherein said cooperating means are further
operative to preload said valve element against said surface to close said
bypass outlet.
Description
FIELD OF THE INVENTION
This invention generally relates to the art of heat exchangers and, more
particularly, to heat exchangers used as oil coolers in vehicular
applications.
BACKGROUND OF THE INVENTION
The use of heat exchangers to cool lubricating oil employed in an internal
combustion engine has long been known. One form of such heat exchangers
currently in use is a so-called "donut" oil cooler. These oil coolers have
an axial length of only a couple of inches or less and are constructed so
that they may be interposed between the engine block and the oil filter,
being attached direct to the block in a location formerly occupied by the
oil filter.
Typically, oil coolers of this type include a multi-piece housing which is
connected to the vehicular cooling system to receive coolant, and which
contains a stack of relatively thin, disc-like chambers through which the
oil to be cooled is circulated. It is common for the upper end of the heat
exchanger to be defined by a stamped, sheet metal filter plate that is
shaped to provide an annular peripheral chamber or dome which serves as a
stabilizing mount for the oil filter when the filter is mounted to the
heat exchanger. Normally, there is a central opening through the oil
cooler through which an oil transfer tube extends to attach the oil cooler
to the engine block and the oil filter to the oil cooler.
It is also common, in such oil coolers, to employ bypass valves to allow
the oil to bypass the disc-like chambers when the oil is at a high
viscosity, as when cold, and obviously not in need of further cooling in
the heat exchanger. This prevents both a large pressure drop in the oil as
it passes through the heat exchanger to the filter and the over
pressurization of the oil cooler housing.
Typically, this bypass function is provided by a spring-biased poppet valve
or a sheet metal flapper valve placed in the oil cooler between the
central opening and the dome of the filter plate. Conventional flapper
valves have a biasing spring that is located and contained by the interior
of the dome of the filter plate, with a flapper extending inwardly towards
the central opening. Conventional spring-biased poppet valves are inserted
in the available area between the central opening and the dome. Both types
of valves work well for their intended purpose.
However, due to current efforts in the automobile industry to increase fuel
efficiency, there have been changes in the construction of the oil coolers
which are incompatible with these conventional types of bypass valves.
One of the changes in construction is directed towards weight reduction and
involves the use of aluminum for the multi-piece housing of the oil
cooler. This presents a problem because standard flapper pressure relief
valves and spring-biased poppet valves cannot be incorporated into the
aluminum housing due to the thicker material gauge and unique construction
configuration dictated by the use of aluminum.
More particularly, due to the thicker material gauge required of the
aluminum construction, the interior of the annular chamber lacks
sufficient size to contain and locate the spring-actuating portion of
conventional flapper valves. The aluminum construction also requires a
support column that extends through the central opening and is joined
integrally with the housing. The size and location of the support column
interferes with the valve-sealing portion of conventional flapper valves.
Additionally, the support column does not allow room for insertion of a
conventional spring-biased poppet valve.
Thus, it can be seen that there is a need for a new, reliable bypass valve
that can be incorporated within an oil cooler having an aluminum
multi-piece housing.
Another change in construction involves an adaptation to allow the oil
cooler to mate with larger diameter, higher flow capacity oil filters.
Increasing the diameter of the oil filter, rather than the length, allows
for higher capacity filters to be installed in engine compartments without
requiring room for additional length. Due to their stamped sheet metal
configuration, conventional domed filter plates are limited as to the
diameter of oil filter with which they can mate. One solution to this
problem has been to replace the conventional domed plate with a flat,
solid filter plate having a sealing surface that extends to the outermost
diameter of the oil cooler. This allows the oil cooler to be mated with
several different diameters of oil filters, including diameters that
approximate the diameter of the oil cooler.
However, the use of the solid filter plate prevents the oil cooler from
using a conventional flapper pressure relief valve. And, as noted earlier,
conventional flapper valves require a dome/annular chamber for location
and constraint. Further, spring-biased poppet valves require additional
oil cooler length which increases the length of the oil cooler-filter
assembly, the very thing sought to be avoided through the use of large
diameter filters. Additionally, some users of such oil coolers are
hesitant to employ spring-biased poppet valves, due to reliability
concerns.
Thus, it can be seen that there is a need for a new and reliable bypass
pressure relief valve which can be incorporated within an oil cooler
having a solid, flat filter plate.
SUMMARY OF THE INVENTION
It is the principal object of the invention to provide a new and improved
bypass valve configuration. More specifically, to provide a simple,
reliable bypass valve configuration that can be used in conjunction with a
donut oil cooler having an aluminum multi-piece housing. It is a further
object of this invention that the bypass valve configuration be easily
accessible and readily replaceable so as to lend itself to serviceability.
In a preferred embodiment, the invention is incorporated in an oil cooler
having a housing with a coolant inlet and outlet, and a surface adapted to
be sealed against an oil filter. The oil cooler includes a plurality of
interconnected heat exchange units located inside the housing, with an oil
inlet to one of the units and an oil outlet from another of the units. An
oil bypass is provided through at least some of the interconnected heat
exchange units and communicates with a bypass outlet in the housing
surface. The bypass outlet is normally closed by a bypass valve which
includes a generally C-shaped, sheet-like resilient flapper with a valve
element sized to close the bypass outlet and located intermediate the ends
of the flapper. The ends of the flapper have feet which are received in
slots in the housing surface to mount the flapper on the surface and to at
least nominally locate the valve element with respect to the bypass
outlet.
According to one facet of the invention, the feet on the ends of the
flapper are oppositely directed. According to another facet of the
invention, the feet are directed radially outward.
According to still another facet of the invention, the valve element is
sized to at least partially enter the bypass outlet so as to close the
bypass outlet. Further, the slots and/or feet are spatially arranged to
preload the flapper and to force the valve element to at least partially
enter the bypass outlet.
In one embodiment of the invention, cooperating means are provided at or
near the ends of the flapper and on the housing surface for connection
together to mount the flapper on the housing surface and to at least
nominally locate the valve element with respect to the bypass outlet.
According to one facet of this embodiment, the cooperating means are in
the form of protrusions carried on the ends of the flapper and apertures
in the housing surface for receiving the protrusions to mount the flapper
on the surface and to at least nominally locate the valve element with
respect to the bypass outlet. According to another facet of this
embodiment, the cooperating means operate to preload the valve element
against the housing surface to close the bypass outlet.
Other objects and advantages will become apparent from the following
specification taken in connection with the accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a side elevational view partially in section of an engine block
having mounted thereon a heat exchanger oil cooler employing a bypass
valve configuration embodying the invention, with an oil filter of the
customary type in position superimposed on the oil cooler;
FIG. 2 is an enlarged, sectional view of the heat exchanger shown in FIG.
1, mounted on the engine block with a portion of the oil filter shown in
dotted lines;
FIG. 3 is a view of the heat exchanger shown in FIG. 2 showing the bypass
valve in the open position;
FIG. 4 is a top view of the heat exchanger shown in FIG. 2 taken
substantially along the line 4--4 of FIG. 2, with a part broken away for
clarity;
FIG. 5 is a view of the heat exchanger generally as shown in FIG. 4 with
the bypass valve removed;
FIG. 6 is a top view of one embodiment of the bypass valve according to the
invention;
FIG. 7 is a rear elevational view of the bypass valve shown in FIG. 6;
FIG. 8 is a side elevation view of the bypass valve shown in FIG. 6;
FIG. 9 is a top view of another embodiment of the bypass valve according to
the invention;
FIG. 10 is a rear elevational view of the bypass valve shown in FIG. 9;
FIG. 11 is a side elevation view of the bypass valve shown in FIG. 9;
FIG. 12 is a top view of yet another embodiment of the bypass valve
according to the invention; and
FIG. 13 is a rear elevational view of the bypass valve shown in FIG. 12;
DESCRIPTION OF THE PREFERRED EMBODIMENTS
An exemplary embodiment of a heat exchanger made according to the invention
is described herein and is illustrated in the drawings in connection with
an oil cooling function for the lubricating oil of an internal combustion
engine. However, it should be understood that the invention may find
utility in other applications, and that no limitation to use as an oil
cooler is intended except insofar as expressly stated in the appended
claims.
With reference to FIG. 1, the block of an internal combustion engine is
fragmentarily shown at 10 and includes a seat 12 which is normally adapted
to receive an oil filter 14. In the case of the invention, however, a
donut oil cooler, generally designated 16, is interposed between the oil
filter 14 and the seat 12. More particularly, the heat exchanger 16 is
held in sandwiched relation between the filter 14 and the seat 12 by an
adapter/oil transfer tube, generally designated 18 and best shown in FIG.
2. The transfer tube 18 has one threaded end 20 that is threaded in the
oil return port in the seat 12 and an opposite threaded end 22 which is
threaded into the central opening of the filter 14.
The seal 24 conventionally carried by the oil filter 14 sealingly engages
one face 26 of a housing 28 for the heat exchanger 16. An O-ring seal 30
is interposed between the opposite face 32 of the housing 28 and the seat
12. As best seen in FIG. 2, the face 26 includes an annular chamber or
dome 36 provided with a planar surface 38 which may be engaged by the seal
24 carried by the filter 14.
As seen in FIG. 2, the oil cooler has a central opening 39 defined by a
support column 41. The transfer tube 18 passes through the central opening
39 so that it may engage both the filter 14 and the block 10.
As seen in FIGS. 1 and 4, the housing 28 includes, on one side 40, spaced
inlet and outlet nipples 42 and 44, respectively, which may be connected
by hoses shown schematically at 46 and 48 in FIG. 1 into the coolant
system for the internal combustion engine.
Turning now to FIGS. 2 and 4, the improved bypass valve construction 50 of
the present invention is seen in greater detail. The construction 50
includes the bypass valve 52 mounted on the face 26. The bypass valve 52
includes a generally C-shaped, sheet-like resilient flapper body 54.
Typically, this body will be made out of a suitable spring steel. A valve
element 56 is located intermediate the ends 58 and 60 of the flapper body
54. The valve element 56 is sized to close a bypass outlet 62 in the
housing surface 26. Radially outward directed feet 64 and 66 are located
respectively on ends 58 and 60, and are received in slots 68 and 70 in the
housing surface 26. The slots 68 and 70 and feet 64 and 66 cooperate to at
least nominally locate the valve element 56 with respect to the bypass
outlet 62.
It will be appreciated, that any suitable cooperating means at or near the
ends 58 and 60 and on the surface 26 may be used to at least nominally
locate the valve element 56 with respect to the bypass outlet 62. For
example, any form of protrusion may be used on the ends 58 and 60 to
engage any form of aperture in the surface 26. Further, the cooperating
means may be in the form of protrusions on the surface 26 which are
received by apertures on the ends 58 and 60 to nominally locate the valve
element with respect to the bypass outlet.
In the preferred embodiment, the valve element 56 is sized to at least
partially enter the bypass outlet 62, as best seen in FIG. 2. Further, the
feet 64 and 66 and slots 68 and 70 are spatially arranged to preload the
flapper 54 and thereby force the valve element 56 to at least partially
enter the bypass outlet 62. This can be accomplished, for example, by
spacing the slots 68 and 70 such that the feet 64 and 66 are compressed
radially inward when in the installed state. This radially inward
compression tends to bow the flapper body 54, thereby forcing the valve
element 56 to enter the bypass outlet 62.
As best seen in FIG. 2, the bypass valve 52 is normally closed, with the
valve element 56 seated in the bypass outlet 62. However, as seen in FIG.
3, when the viscosity of the liquid is high, such as in the case of cold
oil, the pressure of the cold oil is sufficient to displace the valve
element 56 upwardly to an open position, thereby permitting the oil to
pass directly from the heat exchanger as indicated by arrows 72 and thus
bypass much of the volume of the oil chambers 21.
Turning now to FIGS. 6, 7 and 8, the bypass valve 52 is shown in greater
detail, removed from the oil cooler. In this embodiment, the valve element
56 includes an integrally-formed dimpled center 74 which is shaped and
sized to mate with the bypass outlet 62. As best seen in FIG. 7, the
flapper body 54 is stepped, at steps 76 and 78, to join with the valve
element 56. These steps 76 and 78 bias the valve element 56 into the
bypass outlet 62 when the feet 64 and 66 are compressed radially inward
into engagement with the slots 68 and 70. Assembly holes 80 and 82 are
provided in the ends 58 and 60 for engagement with an assembly tool 84
(not shown) which is used to compress the ends 58 and 60 radially inward
so that feet 64 and 66 may be engaged or disengaged with slots 68 and 70.
Another embodiment of the bypass valve is shown in FIGS. 9, 10, and 11. In
this embodiment, the valve element 56 has been coated with a suitable
plastic, elastomeric, or composite material 86 to improve its sealing
capabilities.
Yet another embodiment of the bypass valve is shown in FIGS. 12 and 13. In
this embodiment, the valve element 56 has been provided with a separate
rubber seal 88. The seal 88 is attached to the valve element 56 by two
lock point tabs 90 and 92 which are formed integral with the seal 88 and
which are in locked engagement with mating holes 94 and 96 in the valve
element 56.
Thus, a simple, reliable bypass valve construction 50 is provided for use
in conjunction with a donut oil cooler 16 having an aluminum multi-piece
housing 28. The bypass valve construction 50 is easily accessible and
readily replaceable so as to lend itself to serviceability.
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